Composition for laundering textiles and for imparting a whitening effect thereon



Patented Jan. 6, 1953 COMPOSITION FOR LAUNDERING TEXTILES.-

AND FOR IMPARTIN'G A.WHITENING EF- FECTI THERE'ON' Richard Thomas,Bromborough', England, assignor to Lever Brothers Company, a.corporation of Maine No Drawing; Application April 10, 1946, Serial No.661,070. In Great Britain April 12, 1945 6 Claims; 1 This inventionrelates to washing textiles and compositions adapted therefor. Moreparticularly, it relates to Washing white textile materialswith adetergent composition comprising a substantive fluorescent stilbenederivative which does not darken upon exposure to air, sunlight; orbleaching agents, and to a-detergent composition comprising such astilbene derivative.

It is well known that. white textile materials with the lapse of timeandparticularly after repeated washings tend to lose. their originalbrightness and white appearance and gradually acquire a yellow tint orsimilar ofi-white shade. To suppress or counteract this progressivedeterioration in color it is customary practice in launderingoperationsto. subject the washedmaterial to a blueing treatment. bymeans.- of. a non-substantive; blueing. agent. such as ultram-arinewhich en.- hances the apparent: whitenessof' the; materials; It is usualto give the washed. material, after re-= moval ofvthe. detergent liquid,a plurality of rinses in water and the blueing agent isgeneral-ly addedto the last rinse.

It has been proposed to eliminate the. yellowish or ofi-white tint ofmaterials such: astextile iabrics, paper and. the like -by, treating.the. materials during manufactureor subsequently by'immer sion orotherwise with a solution of a compound of the. coumarin. group,-.preferably beta-methyl unbelliferone. While, however, beta-methylumbelliferone and other fluorescent compounds: of the coumarin group arecapable of achievinga whitening efiect, this. efiec-t. disappears whenthe treated fabrics are rinsed, washed, or otherwise treated inaqueoussolutions, due. to th-e non-sub stantive character of thecoumarin type of compounds.

It has. been proposed to-treattextile materials, in order to impartcolored. fluorescence thereto when illuminated by ultraviolet light,withrelatively large amounts of a stilbene derivative, suchas 4 4dibenzoyldiaminostilbene-2 2 disulfonic acid, which is applied to thetextile in an aqueous bath containing a largev amount of salt, for in.-stance, 20% of Glauber salt. This procedure is obviously notapplicableto laundering processes. Another type ofv stilbene derivative thathasbeen proposed as a fluorescence, imparting agent is typified by 4:4-di-p-aminobenzoyldiaminostilbene- 2:2 -disu1ionic acid. This. type ofcompound is applied tothetextile in an aqueous bathcontaining a largeamount of salt, or salt plus an acid. I. have/observed, howeven that.this type of com-- pound. when presenton. textile fibres, is. likely to.undergo; undesirable changes on; contact with air,.

especially in the presence of strong sunlight, and also with oxidisingagents, for instance, bleaching agentsof the sodium hypochl-orite type,with the result that the textiles become gradually discolored.Therefore, this-agent is not suitable for imparting lasting whiteness towhite textile materials, especially if the treated textile issubsequently subjected to a conventional bleaching treatment. The amountof the stilbene derivative in these particular materials which arintended to be decorative or clearly visible in ultraviolet light mustbesuch as to impart a brilliant colored fluorescence when subjected toultraviolet light in the absence of light in the visible portion of thespectrum. The color or appearance imparted to. these textiles underordinary daylight by the stilbene: derivatives is not of any greatconcern, and. there has been no proposal to use small amounts ofstilbenefiuorescent compounds to obtain a whitening effect in ordinardaylight.

It has been proposed to treat textileswith a stilbene derivativecontaining at least one triazine nucleus in the molecule. in order toimpart a whitened appearance to the textile. However, such materials aswere obtainable from a commercial supplier showed unsatisfactorystability properties.

It: has: been found, and quite unexpectedly, that the above discusseddisadvantages can be sub.- stantially eliminated and an improvedwhitening efiect of greater stability and durability can be obtained byusing as a treating agent a combination of a detergent. and ablue-fluorescent compound which is a derivative of adi-aminobenzoylaminostilbene-sulfonic acid in which at least one of thehydrogen atoms in-each of the NI-Iz radicals attached to the terminalrings is substituted'by an organic radical which does not contain an NHzradical directly attached to an aromatic nucleus and which would notitself render the substituted compound formed unstable to light andoxygen. The improved whitening efi'ect and greater stability can beimparted to white textile materials, particularly cotton, linen, andother cellulosic materials.

In the-laundering of white articles, sodium hypochlorite and similarbleaching agents are often used in the wash or in the rinse to improvethe color of the material or to remove fruit, tea, coffee and similarstains. We have found that the whitening efiect produced when using thespecified stilbene derivatives of the invention is not impaired by suchtreatment, as contrasted with the. detrimental effect of such treatmenton the stilbene derivatives mentioned earlier in this specification.

The objects achieved in accordance with the invention include theprovision of a laundering process for washing and imparting an improvedwhitening effect of great stability to textile materials; the provisionof laundering compositions comprising a combination of a detergentsuitable for washing textile materials and a small proportion of anaminostilbene derivative adapted to impart an improved whitening effectof great stability to textile materials; and other objects which willbecome apparent as the invention is described in more detailhereinafter.

The process aspects of the invention comprise the step of treatingtextile materials to be washed in an aqueous bath containing a smallproportion of an aminostilbene derivative of the kind specified, in thepresence of a detergent. This is preferred since it is more convenientto incorporate the aminostilbene derivative in the detergent and thepresence of the detergent does not interfere in any way with theenhanced whitening effect of the specified stilbene derivatives.

Instead of adding the specified stilbene derivatives to the wash liquor,they may be applied during the preliminary treatment of the soiled I XNmaterials which usuall precedes the washing operation proper. It is acustomary practice in domestic laundering to allow the soiled materialsto soak for several hours, as this removes much of the soluble or loosedirt and facilitates subsequent washing. In commercial laundries a shortpreliminary soaking treatment is carried out by mechanically agitatingthe materials for a few minutes in water which is usually made slightlyalkaline. This preliminary treatment is called the break. The specifiedstilbene derivatives may be added to the break.

The detergent promotes cleaning of .the soiled white textile materialsby facilitating the removal of material adhering to the textilematerial. In the treating process of the invention, the whitening of thetextile material with the aminostilbene derivative takes place eithersimultaneously with the washing-detergent action or is followed by thewashing-detergent action. In either method, the textile is subjected tothe effect of the combination of the detergent and the aminostilbenederivative.

It might be expected that the simultaneous or subsequentwashing-detergent treatment would interfere with the absorption of theaminostilbene derivative by the textile, or that the subsequentwashing-detergent treatment would remove any absorbed stilbenederivative. This is not the case, however. Instead, the presence of thedetergent, along with the particular aminostilbene derivative used inaccordance with the invention, results in an unexpected whitening actionat the conclusion of the washing process, and this is not destroyed byrinsing or subsequent treatments.

The accumulation of the substantive whitening agents of the invention onthe textile material, such as by repeated laundering treatments, is notharmful. It is not possible to over-blue the textile therewith. In thisrespect the new agents are distinctly different from substantive bluedyes. Any accumulation of the aminostilbene derivatives of the inventionon the textile is harmless, not only from the standpoint of appearanceimmediately imparted to the textile but also from the standpoint offreedom from potential darkening. The stilbene derivatives of theinvention do not darken on exposure to air, sunlight, or bleachingagents, such as sodium hypochlorite. Thus, the treated textile materialcan be laundered repeatedl in accordance with the invention withoutharmful efiects.

The above defined stilbene derivatives, for example, may be derived bysubstituting in a diaminobenzoylamino-stilbene sulfonic acid, such as4:4-dip -aminobenzoylamino stilbene-2:2-disulfonic acid,4:4-di-p-aminobenzoylamino-stilbene-3:3-disulfonic acid,4:4-di-p-aminobenzoxylamino stilbene-2:2,6:6-tetrasulfonic acid, one orboth amino hydrogen atoms by an organic radical which does not itselfcontain a terminal NHz radical attached to an aromatic nucleus such as abenzene ring. It is essential that the aminostilbene derivative containno primary-amino aryl groups in the molecule.

At least some of the aminostilbene derivatives which may be used inaccordance with the invention may be illustrated by the followingformula:

SOaH SOsH Y CH=CH where X is alkyl, aryl, aroyl, acyl, or carbamyl, andY is H, alkyl or aryl. In general, the lower aliphatic or aromaticgroups are preferred as the X in the above formula. These may betypified by: methyl, ethyl, propyl, isopropyl, butyl, cyclohexyl,phenyl, methylphenyl, dimethylphenyl, benzoyl, methylbenzoyl,dimethylbenzoyl, acetyl, propionyl, butyryl and carbamyl (H2NCO-),methyl carbamyl (HzCNHCO), ethyl carbamyl (H5C2NHCO) and d i e t h y lcarbamyl (HsCz) 2NCO) The stilbene derivatives may contain one or moresulfonic acid groups and these may be attached anywhere in the molecule.The stilbene derivative may be of the symmetrical type or nonsymmetricaltype. The benzoyl group may be replaced by a corresponding polynucleararoyl group. Thus, in the broader aspects of the invention, a(non-primary amin0)aroylaminostil- ,bene sulfonic acid is used as thewhitening agent. The non-primary amino groups which are directlyattached to an aryl group may be secondary (i. e. RNH) or tertiary (i.e. R2N), as long as R does not contain a primary amino (-NHz) groupdirectly attached to any aryl group.

The above defined stilbene sulfonic acids may be used in the form oftheir salts (i. e. sodium salt) and it is intended that the term acid"appearing herein include the acid itself and also derivatives such asthe salts which contain the anion of the acid.

The aminostilbene derivative must be water soluble or dispersible in thepresence of a detergent and this will exclude groups which impartthereto non-dispersibility in water.

The aminostilbene derivatives used in accordance with the inventionshould not contain a group or radical which imparts tinctorialproperties (i. e. an actual color producing or chromophorous group) orgroups which tend'to discolor upon exposure to light, air, or bleachingagents rivatives which may be used in accordance with I l the inventionare:

1. 4:4-di-p-benzoylaminobenzoylamino stilbene-Z :2. -disulfonic acid;

soar

CH=CH 2. 4'z4"-di p acetylaminobenzoylamino-stilbone-2: 2' -disulfonicacid;

SOsH

aswell as'the corresponding metaand ortho com.- pounds, and salts of.the above acids.

The detergents that are used with. the stilbene compound or subsequentthereto or which are: combined with the stilbene compound inacomposition, are of the kind suitable for and customarily used intextile laundering practice. The suitable detergents are generally ofthe organic detergent type.

Thezorganic detergents are regardedby'the art as falling into the soapyand the non-soapy-types; The water dispersible soapy organic detergentsare salts ofsoap-forming carboxylic acids such as the fatty acids, rosinacids, and the like. The cation of the water dispersible soap is usuallymonovalent and usually an alkali metal cation such as sodium.

The non-soapy organic detergents generally are not carboxylate salts. Ingeneral, they have in the molecule a. group having hydrophobicproperties, such as a long chain alkyl radical, and a group havinghydrophillicproperties, such as: a sulfonic group. The non-soapy organicdetergents comprise, for example, sulfonated or sulfated high molecularfatty compounds, which are known in the art as a group of non-soapyhigher fatty detergents. Some of the various compounds of this typeinclude sodium fatty a1- cohol sulfates known as Gardinols, isethionicacid, hydroxy ethyl sulfonic acid and sarcosine condensation compoundsof fatty acid radicals having 8 carbon atoms or more, such as Igepon A;amides of various types, such as Igepon T and. Emco, and Nacconols whichare alkali metal alkyl aryl sulfonates.

The expressions soap product and detergent product refer to products ina commercial marketable form comprising primarily soap or the non-soapyorganic detergents, or both as the active organic detergent, inadmixture with appropriate proportions of water, glycerine, filler,antioxidant, coloring matter, and other soap adjuncts present in largeor. small amounts as impurities or additives for special purposes. Thefillers or builders which may be included in the soap product or thedetergent product are typified by sodium carbonate, sodium silicate,various phosphates, and other well known soap adjuncts.

A preferred embodiment of the invention comprises a compositioncomprising a detergent,

6 preferably ordinary laundry soap, and; a small amount of: the above.aminostilbenederivative; Thev proportions: of. the; detergent. andaminostilbene derivativev in the composition are determined by variousfactors such as the particular aminostilbene derivative employed, thenature of the textile material, the nature of the detergent, and theconcentration of the detergentv composition which is to be used in theaqueous dispersion or washing solution. As a general rule, less thanabout 1% of the aminostilbene is required, based on the Weight of thedetergent, and proportions ranging from about 0.001% to 0.1% have beenfound suitable for usualtextile washing procedures;

The. compositions may be in any convenient form, such as tablets orcakes of framed, milled or. convertedsoap; flakes, and powder orgranules,- such as spray dried soaps, comprising the amino.-stilbenederivative. In general, the powder or granule-form. isconvenient for. general. launderingv purposes.

In; the preparation of the compositions, in accordancewith-theinvention, the. aminostilbenederivative may be incorporated with thedeter-- gent atany'suitable stage of manufacturing, for example-,in-thefinal stage in the soap kettle, or. during the crutching or milling ofsoap. The aminostilbene compound may be added in the formof a solutionor suspension in water, or in admixture with other ingredients, such. asperfumes, antioxidants, or any other adjunct to be included in thefinalsoap product.

The requisite amounts of aminostilbene compounds in the washing liquoror in the preliminary laundering treatment may vary within' wid'elimits. In general, it is preferred to express this in terms of theamount of textile to be treated, and usually not over about 0.01'% \isnecessary,- based on the dry weight of the textile material to bewashed. Propertions ranging from 010025 to 0.000175 have been foundsufficient to impart an appreciable whitened effect. There is noadvantage in using more than is necessary to obtain the White effectand, of course, the amounts used should be less than sufficient toimpart a colored effect thereto. The amount need not be larger than0.05%, based onthe textile: material to achieve a satisfactorywhitening. effect. However, since the use: of. excessive quantities ofblue-fluorescent sub.- stances does notin general produce over-blueing,which is an objectionable feature of. the commonly used blueing agents,higher amounts,.say upto one per. cent. or-more, maybe used withoutdetriment to the effect produced. Such higher amounts, however, usuallyserve no useful purpose once the quantity producing maximum whiteningeffect for a given case has been reached.

If the detergent composition contains 0.01 to 0.075% by weight of theaminostilbene compound and the washing liquor contains 0.25 to 0.75% ofthe detergent composition, the concentration in the liquor of theaminostilbene compound can be readily calculated.

7 The manner -of applying. the invention in tiles and for imparting awhitening eflect thereto practice is illustrated in the followingexamples. comprising a detergent suitable for laundering The detergentemployed wa ordinary laundry [textiles and from about 0.001% to 1% byweight soap and the aminostilbene derivative was the of anaminoaroylaminostilbene sulfonic acid sodium salt of 4:4-di-p-acetylamino-benzoylwhich has the following general formula:

S0111 SOaH Y Y 21-1 CH=CH N-X amino-stilbene-2:2 -di-sulfonic acid.Laundry where X is a radical selected from the group compositions weremade up therefrom, compris- M consisting of aroyl and acyl radicals andY is a ing various proportions of the aminostilbene deradical selectedfrom the group consisting of hyrivative. This compound was incorporatedin drogen, alkyl radicals of not over four carbon the soap inproportions varying from about atoms, phenyl, methylphenyl anddimethylphenyl 0.003% to 0.06% of the weight of the soap, and radicals.

the resulting soap products were used for wash- 2o 3. A compositionsuitable for laundering texing white cotton and linen materials in aseries tiles and for imparting a whitening effect thereto of comparativetests. The wash liquor was made comprising soap and from about 0.001% to1% by up by dissolving about 0.4% of each soap prodweight of abenzoylaminobenzoylamino-stilbene uct in hard water. The materials werewashed sulfonic acid free from terminal NHz groups atboth at about 40 C.and at the boil, rinsed three tached to an aryl group.

times in clean water and then dried and ironed. 4. A launderingcomposition comprising soap It was found that in every case the finishedmaand from about 0.001% to 1% by weight of an terials were of abrilliant white appearance and acetyla n be y o-St 1bcne SulfOnic acidthat the whiteness was not noticeably impaired e m terminal z o pstached to an when the materials were exposed to sunlight for arylgroupprolonged periods. The higher proportions of 5- A c mpo i n i l forla nd rin texthe blue-fluorescent compound gave the best retiles and forimparting a Whitening efiec e o, sults, but even the lowest proportionsshowed a p s ng Soap and from about 0.001% to 0.1% marked improvement.subjecting the above by W i h of -P- z yl mi z yl miwashed materials toa. sodium hypochlorite bleach ti1be e-2I2 -disulfonic acid. treatmentdid not darken the color thereof. A COmDOSitiOII Suitable for launderingte The foregoing descriptions of specific embodi- $1165 and forimparting a Whitening effect thereto. ments of the invention are forillustrative pur- Comprising p and from about ii-001% to 0.1% poses onlyand are not to be construed as limiy W ht o 4I4 -d-pacetylaminobenzoylaminotations of the invention as it is otherwisedis- -diSulfonic acid. closed and claimed herein. In view of the fore-RICHARD THOMAS. going disclosure, variations and modifications thereofwill be apparent to one skilled in the art. REFERENCES CITED Theinvention contemplates all such variations The following references areof record in the and modifications as come within the scope of file ofthis patent: the appended clalms- UNITED STATES PATENTS I clam: NumberName B g 1. A composition suitable for laundering texe tiles and forimparting a whitening effect thereto 2089413 Fame et a1 1937 comprisingsoap and from about 0.001% to 1% by FOREIGN PATENTS weight of anaminoaroylaminostilbene sulfonic Number Country D te acid which has thefollowing general formula: 731,558 Germany Feb, 11, 1943 S0311 SOsH X-Il CH=CH I l-X U where X is a radical selected from the group con- OTHERREFERENCES sisting of benzoyl and acetyl radicals and Y is a radicalselected from the group consisting of hy- 5 Wench; (3-), publlsheddrogen, alkyl radicals of not over four carbon atoms, phenylmethylphenyland dimethylphenyl pagilililgcal Formulary-Bennett. Vol. 6 (1943)radicals.

2. A composition suitable for laundering tex-

2. A COMPOSITION SUITABLE FOR LAUNDERING TEXTILES AND FOR IMPARTING AWHITENING EFFECT THERETO COMPRISING A DETERGENT SUITABLE FOR LAUNDERINGTEXTILES AND FROM ABOUT 0.001% TO 1% BY WEIGHT OF ANAMINOAROYLAMINOSTIBENE SULFONIC ACID WHICH HAS THE FOLLOWING GENERALFORMULA: